In Germany for example, that isn't allowed, and there is the whole insurance discussion if something happens to someone that shouldn't be there as employee in first place.
It also works for people willing to take time off (PTO or otherwise). We do lose some people who aren't willing to do the trial, but that's considered acceptable. People who do the work trial and accept an offer are much more likely to stick around (much lower rate of mistakes on their part and our part.)
I'm laughing a bit at Germany, but Europe in general has lost the plot when it comes to innovation.
In Germany for example, that isn't allowed, and there is the whole insurance discussion if something happens to someone that shouldn't be there as employee in first place.